When Galaxies Collide, The Milky Way and Andromeda on Collision Course…

Scientists have this week announced the Milky Way and Andromeda are on collision course! If no action is taken, if courses aren’t corrected, in four billion years from now a new apocalypse will approach.

Andromeda, The Milky Way’s nearest galactic neighbor is on a slow motion collision course with the galaxy in the next lane, our galaxy. Currently more than 2.5 million light years away and moving towards us at roughly 110km per second it may be time to toot our horn, flash our headlights or brace for impact.

Included for your viewing pleasure is the latest stunning video simulation of this interstellar event of immense proportions. Impressively the team were also able to generate renderings of the night-time sky in the aftermath, an amazing preview.


Scientists have for decades suspected that the two galaxies would eventually cross paths, to the great consternation of both galaxies inhabitants. Using Hubble to study Andromeda’s movement in greater detail than ever before, astronomers Roeland van der Marel and Sangmo Tony Sohn have created the most accurate simulation to date. The simulation not only confirms the collision course and for the first time provides a time frame. So confident are the scientists that they are willing to make the risky move of publishing the date of this spectacular apocalypse, 4 billions years from now, at 12.30 pm.

Till now scientists have only been able to estimate the velocity of Andromeda along the line of sight, it’s coming straight for us, but the angular velocity, sideways, is also required to estimate Andromeda’s trajectory. To achieve this Hubble has for 8 years tracked 15,000 stars within the Andromeda galaxy. Measuring the slightest movement of the study group, Hubble’s incredible level of detail was able to allow the astronomers to track the group relative to each other and as a collection.

As impressive a spectacle as this may be, especially when viewed from the outside, it may not be as destructive as the video would suggest. The co-mingling and formation of a single galaxy is driven more by gravity than it is cataclysmic impacts. The spacing between the solar systems that make up both galaxies is so great that impacts during the collision will actually be relatively rare.

Not to say that it will be as simple as shuffling two decks of cards together, this will after-all be a 3 billion yearlong coalescing of two great solar systems. 3 billion years of gravity stirring solar systems together, giving birth to a new super galaxy, The Milky Andromeda Way perhaps.


The numbers also seems to suggest that our Sun will find a new home in the outer reaches of the new super galaxy, with a 10% chance the Sun will end up parked more than 160,000 light-years from the new galactic center, currently estimated to be between 22,000 and 28,000 light years from the Milky Way’s center.

Hubble and these advanced observation techniques are not only being put to headline grabbing calculations. The little corner of the universe we call home sees us surrounded by other solar system. This cluster is called the local group of galaxies, a sub-component of the Virgo Super-cluster. Astronomers hope to put Hubble to work studying the Local Group using similar simulation techniques to observe the evolution of these galaxies.

Satellites such as Hubble are our eyes in the sky’s, helping us to see clearer than ever before, helping us to understand the universe we live in. If ever you find yourself contemplating the limits of knowledge, if your ego raises its thorny head to suggest ‘we must nearly know all’, take a look for a moment through Hubble’s eye, focused on the distant, the ancient. Be reminded knowledge knows no limits